Call switch for signal systems



Feb. 24, 1931. w. P. CROCKETT 1,793,999

7 CALL SWITCH FOR SIGNAL SYSTEMS Filed Nov. 7. 1928 2 Sheets-Sheet 1 Feb. 24, 1931. w. P. CROCKETT 1,793,999

CALL SWITCH FOR SIGNAL SYSTEMS Filed Nov '7, 1928 2 Sheets-Sheet 2 m N xx Q n x u aitanzey Patented Feb. 24, 1931 UNITED ETATEE WILLIANE P. CROCKET'I, OF CHICAGO, ILLINOIS CALL SWITCH FOR SIGNAL SYSTEMS Application filed November 7, 1928.

The signal s itch invention relates to a call switch for systems, and particularly to a call which may be used in hospitals, or er places, to be operated by a patient, or o er person, to call a nurse, or other attendant, who after responding to the call resets the call switch so that it will be in order for i extoperation by the patient.

The pr sent invention is an improvement over that shown and described in my Patent N umber 1,620,951, issued March 15, 1927. In the patent referred to, the greatest burden of operation of the device is upon the patient who is required to operate the call switch against the tension of a spring, and a certain amount of friction, whereas the nurse or attendant has the more simple operation of merely pressing the slidable latch against the action of a much weaker spring and a lesser noun-t of friction.

In the present invention the greatest burden of operation of the device is transferred from the patient, who may be in a very weakened condition, to the nurse, or other attendant, who is usually in robust health. In other words, the nurse or attendant is compelled to push the slide button of the call switch againstthe spring contained therein having the greatest tension, and a certain amount of friction, while the patient, in whatever weakened condition, may quite initiate a call by pulling a chain or cord against the action of a relatively weaker spring and less friction.

Heretofore in the case of operation of many forms of call switches for hospital signal systems, the burden upon the patient, has been too he; vy, and engineers and architects have endeavored to remedy the situation by placing the call. switches in various positions relatively to the bed of the patient so that the difficulties encountered would be overcome. In the present invention these difliculties have been overcome and the call switches may be placed anywhere in the wall, or other Serial No. 317,807.

support, and may be readily operated by thetient from any position.

The invention will be further understood by reference to the accompanying drawings illustrating one embodimentthereof, althci gh. it will he understood that changes therefrom may be made without departing from the spirit of the invention as set forth in the appended claims.

T the drawings:

l is a front elevation of the call switc and shows the front plate thereof with the pull cord to be operated by the patient, this cord being shown in various positions.

Figure 2 is rear view of the call switch mounted on the front plate.

Figure 3 is vertical cross sectional view of the call switch on the line 33 of Figure 1 ows the switch set with the visual illuminated. n igure f is a front view of the call switch with the cover plate removed and on the line 4- l Figure 3.

Figure 5 is front view of the switch slide on the line of Figure 3.

Figure 6 is an enlarged sectional view of the latch member and showing the method of insulating the pull chain and is on the line 7-7 of Figure 3.

Figure 7 is a diagrammatic view showing the various electric light and buzzer circuits operated by the call switch.

Figure 8 is a longitudinal central sectional view of the call switch showing the condition thereof after having been reset and with the lights out and the buzzer not in operation.

Figure 9 is longitudinal sectional view of the call switch showing the condition of the parts thereof with the lamps illuminated and the buzzer not in operation.

Figure 10 is a longitudinal central sectional view of the call switch showing condition of the parts thereof with the lamps illuminated and the buzzer in operation.

-' Figure 12 is a transverse sectional view on the line 1212 of Figure 9, and

Figure 13 is a transverse sectional View on the line 13-13 of Figure 10.

By referring to Figure 7 which shows the circuit which is preferably used in connection with the call switchof the invention, the purpose of the invention may be readily understood. A source of current supply, such as the battery 15, isconnected between the main lines 16 and 17. The signaling devices for the respective stations will be connected to the main lines each in the manner indicated. V

The calling switch mechanism is provided with a movable switch element 18, provided with arms or prongs 19, 20,21, and 22 and provides a movable switch for cooperation with the fixed contacts 23, 24, 25, and 26.

One main wire 17 is connected with the contact 23 and when the switch element 18 is moved into connection therewith it. will also contact with fixed contacts 24, 25, and 26. Contact 24 may control a door lamp 27 arrangen in a connection 28 from said contact to the main wire 16, and also a call lamp 29 arranged in a parallel connection 30. 'Either or bothof these visual signals may be employed for indication at the door of the sending station or at some nurses station in the hospital, or other place, and of course other parallel connections from this contact to othr signal devices may be employed if desired.

The contact 26 may be connected through a common wire 31 with like contacts of other signal-initiating stations and th s wire 31 may be connected as at 82 through the lamp 33 to 1e main wire 16, so that the lamp 33 may serve as a pilot common to a plurality Oi signal-initiating stations The contact may be'connected through a common wire 34 with like contacts of other signal-initiating stations and this wire 34 I may be connected through a lamp 35 to the main wire 16, so that the lamp 35 may serve a pilot common to a plurality of signali itiating stations.

Provision of ano auxiliary contact 36 with a contact 63 is made through conductor fitted into an aperture in the wall, or other support, but it will be understood that it may be attached to the wall, or other support, in any suitable manner, or it be placed in a container and suitably supported.

As shown, the call switch is provided with the cover 41 which carries the operating parts of the call switch. The switch is secured in the wall means of the screws 42 and 43, or other suitable fastening means.

To the rear face or under side of the cover an insulating base or block 44 is secured, as bi screws 45, the other face of this block be a vertical direcing channeled, as 46, in tion for reception of the sliding switch 18 ltS associated parts. The slide bar 47 has suitably secured to it, as by riveting, the four pronged contact plate or switch 18, and to the upper end of the slide bar 47, and suitably insulated therefrom, is secured a slide button, generally designated 48.

The slide 47 is provided with the slots 49, 50, and 51. The slots 49 and 50 are rectangular, while the slot 51 has its lower portion rectangular and its upper portion 52 circular. Guiding screws 53 and 54 are secured in the base or block 44 and pass through the slide bar 47 and guide the latters vertical movement.

The switch element 18 and the slide bar 47 being secured together coact at all times. The

four extensions or prongs of the switch element 18 and numbered 19, 20, 21 and 22, are brought into connection with the respective fixed or stationary contacts, 23,24, 25, and 26.

The stationary contacts 23, 24, 25, and 26 have appropriately shaped heads integral with stems 55 which project through the back of the base or block 44to act as binding posts, V

The relatively strong coiled spring 56 is located in the recess 57 in the base or block 44. A boss 58 is secured to the slide bar 47 and has its stem extending through the slide bar into the recess 57. The top of the spring 56 in constant engagement with the stem of the boss 58 and through the instrumentality of the boss 58 exerts an upward force on the slide bar 47.

A latch or plunger 59 having enlarged head portions 60 and 61 of two different diameters is placed in an aperture extending through the lower nd of the base or block 44. The latch or plunger 59 is provided at itsrear end with screw threads adapted to receive the nut 62. The nut 62 is formed with two different diameters, the larger diameter being to therear.

Interposed between the nut 62 and the base or block 44, is the relatively weak leaf spring 63. The lower end portion of the leaf spring 63 is provided with an aperture through which the threaded end of the latch or plunger 59 extends. The'lower end portion of the leaf spring 63 presses rearwardly against the portion of the nut 62 having the larger binding post- 65.

diameter. The leaf spring 63is secured at 'its opposite and upper end to the screw 53 by means of the lock nut 64.

The lower end of the leaf spring 63 is adapted to make contact with the strip contact 36. It is important that proper adjustment between the end of the leaf spring 63 and the strip contact 36 be maintained and accordingly the nut 62 should be firmly secured to the rear end of the plunger or latch 59, as by soldering.

The contact 86 extends from adjacent the rear end of the latch or plunger 59 to the 7 A conductor bar 66 extends across the rear ofthe base or block 44 from the binding post to the binding post 67 furnishing a connection for an additional signal, such as another buzzer. The conductor bar is apertured to permit reciprocation therethrough of the latch or plunger 59.

The construction of the head of the latch or plunger 59 is shown in the enlar ed detailed view in Figure 6. A metallic ball pull chain 68, or other suitable means, such as a cord, is used to operate the plunger 59 against the action of the spring 63. The head of th enlarged portion 61 of the plunger is drilled to form the recess 69 into which the first wall of the chain is placed.

A fiber disc 70 having a radial slot 71 is inserted between the first and second balls of the chain, a metallic ring collar 72 is placed on the enlarged portion 61 with its edgessuitably flanged over the enlarged portion 61 and the fiber disc. By this means the ball chain 68 is secured to the plunger 59, the insulating disc 70 is clamped to the head of the plunger and thus the metallic ball chain is held in place and insulated from the metallic plunger 59.

The cover plate 41 is apertured at its lower portion, opposite the latch or plunger 59 to permit the metallic pull chain 68 to be operated therethrough. The aperture is formed with the outwardly extending flange 73 and metallic sleeve '7 4 and is suitably secured to the cover plate 41 and is fitted within the flange 73.

The sleeve 74 is formed in such a manner that the metallic ball chain 68 may operate the plunger 59 without any interference whatever. The inner face of the sleeve is so curved that no matter from which direction the ball chain may be pulled by the patient, the chain will not catch or bind.

.The operation of the device is as follows, and in this connection reference may be had. to Figures 8 to 13 inclusive:

In Figure 8 the call switch is shown with the lights unilluminated and therefore iving no visual signals at the receiving stations. The audible signal or the buzzer also is not functioning, as shown in this figure. The slide button 48 is in its depressed condi the respective contacts tion, and, since it is connected to the slide bar 47, although insulated therefrom, it has de pressed the slide bar 47 to its lowermost position, carrying with it the boss 58, with its stud extending into the recess 57, and has caused the sprin 56 to be compressed.

At this time the latcii or plunger 59 is in its inne ost position with the head por tion 6O 01 smallest diameter in the circular recess 52 the slide 47. The latch or plunger 59 lbeen brought to this position previ as y by the action of the leaf spring 63 against the nut 62, the nut being soldered to th plunger 59. It will be seen that the lower end of the soring 63 does not contact with the strip contact 36.

By reference to Figure 4 it will be seen hat when the slide bar 47 is in its depressed osition shown in Figure 8, the prongs 19, O, 21 and 22 are not in contact with the re- "pective contacts 23, 24, 25, and 26 and thereiore the visual signals or lamps are lllllllulnlnated.

.Vhen the patient desires to cause the visual )ulls the metallic ball. chain 68 which in turn pulls the latch or olunger 59 from the posi tion shown in Figure 8, so that it operates hown in Figure 9. hen the plunger 59 is pulled, stated, the slide bar 47 is readily released from the plunger 59 and is moved upwardly through the action of the spring 56 against the boss 58.

At this time the stem portion of the plunger enters the slot 51 located in the lower portion of the slide bar 47. The slide button 48 is now in its uppermost position and the 1.9, 20,21, and 22 are conta ting with 23, 24, 25, and 26 'nal or lights. It

, t this time the lower end of the leaf eprir although brought forward a sli ht distance, remains out of contact with the strip contact 36 and consequently since no current flows through the leaf spring 63 and. the contact 36, the audible signal or buzzer is not operated.

In order to cause the audible signal to operate or ring the buzzer for the nurse, or other attend ant, the patient in: pull on the metallie all. chain 68 slightly iore than done to cause the illuminati n the visual signals. T is is shown in 10 where the call switch shown continuing to operate the visual signals.

The pull the chain plunge 59 a little further than the iron shown in Figure 9 and ses th end of the leaf S -n'ing 63 to inal-Ie contact with the strip contact This is also shown in Fig which is the tr isvcrse view of the parts illu inating the visual will be noted however pulls the latcl :ignals to be put in operation. the patient lucthe-operation oi theaudible signal, is caused only while the patient is-pulling the plunger 59 and causingthe end ot'the leaf spring 63 to contact with the strip contact 86. On re lease oi thechain or cord ti while the buzzer ceases ringing the lainos still remain illuminated. It is only by the downward operation of the slide button 48 and theflconsequent breaking of the circuits atthe contacts 19, 20, 21, and22, and 23, 24, 25, and 26, respectively, that the lamps are extinguished.

1 bar It will be seen from the foregoing statement of the operation of the call switch that when the chain or cord 68 is pulled,, the slide a; with its slide button i8 is operated only in'an upward direction but is never operated in a downward direction or a set posi-' tion. The onlyway in which the call switch may be reset to extinguish the lights is for the nurse, or other attendan'ato push down on the slide button 48 which in turn pushes downwardly the slide bar 47 and compresses tlIBS'HHl 56 throu h the medium of the boss l a 5,8. The action'ot the leaf snrin 63 because L b of the nut 62 soldered to the plunger 59,

causesthe plunger 59 tobe drawn rearwardly into position inthe slot 52 where it is held against the slide bar 47.

-Having thus described the invention what I claim and desire to secure by Letters Patent contact members to elevate them to circuitclosing position, an insulated slide button for depressing said contact members and bar to circuit opening position, means for latching said contact members and bar in circuit opening position, comprisinga plunger of two diameters extending into said latching slot for the latched and unlatched positions, respectively, of said slidable bar, a relatively weak leaf spring secured to said insulating base, said leaf spring having one end apertured, said plunger having one end extending through said aperture, and a cap on said end of said plunger to retain said leaf spring and said plunger in cooperative relationship,

I said plunger being operable by a pull chain or cord in a direction transverse to the movement of said slide bar to unlatch said slide bar and cause the contact members and said slide bar to close said signaling circuits, and means whereby a further pull upon said plunger causes an additional signaling circuit to be closed, said means consisting of a strip contact intermediate the said insulat-.

support, an insulating base carried by said plate, a movable contact member slidably mounted on said base for movement relative thereto, fixed contact members for inclusion in signaling circuits mounted on said basefor coaction with said movable contact member, a spring acting on said movable contact to elevate it to circuit closing position, manual means for depressing said movable contact member to circuit opening position and 7 means for latching said movablecontact member in circuit opening position, comprising a plunger extending through said insulating base, said plunger having a head of two diameters, said head having a recess, a metallic pull chain, a disc of insulating material extending over said recess and'slotted to receive the end of said pull chain, andmeans securing said disc to said head.

3. Electrical switch means of the character described, comprising the combination or" a fixed insulating base, a contact bar mounted for sliding movement on said base and having contact making and opening positions, electrical contacts carried by said base for engagement with said bar in its contact making position, a relatively strong spring tending to move said bar to its contact making position, manually operable latching means holding said bar in its contact opening position, said latching means comprising a shouldered plunger carried by said base and extending transversely through said bar, said bar being slotted to receive the shouldered portion of said plunger to hold said bar in itscontact opening position against the action of said spr ng and permitting movement of said bar to its contact making position for a second position of said plunger, and a relatively weak spring tending to hold said plunger in its bar holding position. i

4. Electrical switch means of the character ing to move said bar to its contact making position, manually operable latching means holding said bar in its contact opening position, said latching means comprising a shouldered plunger carried by said base and extending transversely through said bar, said bar being slotted to receive the shouldered portion of said plunger to hold said bar in its contact opening position against the action of said spring and permitting movement of said bar to its contact making position for a second position of said plunger, a relatively 5 Weak spring tending to hold said plunger in its bar holding position, said plunger having a third position for the released condition of said bar,and additional electrical contacts closed by movement of said plunger to said third position.

In Witness whereof, I hereunto subscribe my name this 29th dayof October, A. D. 1928.

VILLIAM P. CROCKETT. 

